The invention relates to apparatus for assemblying a wall module and more particularly to apparatus for assemblying a wall module from a pair of stretched sheets of metal laterally spaced apart by a skeletal frame with the interior of the wall module to be later filled with structural foamed plastic.
The type of wall module that is being assembled in the novel apparatus is one that is used on a transportation vehicle such as a bus. The wall module is normally used for the roof of such a vehicle although the apparatus has been used to form wall modules for the floor of such a vehicle.
The manufacture of wall modules for a transportation vehicle is unique. The generally accepted method of manufacturing a wall for a vehicle such as a bus is to attach a frame to the chasis of the vehicle and then to cover its inner and outer surfaces.
A method and apparatus for making laminated panels of polystyene foam and aluminum is described in U.S. Pat. No. 3,410,931 but this patent is not directed to making wall modules for a transportation vehicle and the unique problems that would be encounted in making such a wall module.
It is an object of the invention to provide a novel apparatus for assemblying wall modules from sheet metal on a coil.
It is another object of the invention to provide a novel apparatus for stretching sheet metal prior to assemblying it in a wall module.
It is also an object of the invention to provide a novel apparatus for maintaining a pair of sheets of metal in a stretched condition while they are pierced riveted to a skeletal frame sandwiched therebetween.
It is a further object of the invention to provide a novel apparatus having a first elongated sheet metal stretcher assembly mounted vertically over a second elongated sheet metal stretcher assembly.
It is an additional object of the invention to provide a novel method of assemblying a wall module from elongated strips of sheet metal.